Buggy code:
public class Facade implements IFacadePart2 { @ Override public Mazub createMazub ( int pixelLeftX , int pixelBottomY , Sprite [ ] sprites ) { } @ Override public int [ ] getLocation ( Mazub alien ) { } @ Override public double [ ] getVelocity ( Mazub alien ) { } @ Override public double [ ] getAcceleration ( Mazub alien ) { } @ Override public int [ ] getSize ( Mazub alien ) { } @ Override public Sprite getCurrentSprite ( Mazub alien ) { } @ Override public void startJump ( Mazub alien ) { } @ Override public void endJump ( Mazub alien ) { } @ Override public void startMoveLeft ( Mazub alien ) { } @ Override public void endMoveLeft ( Mazub alien ) { } @ Override public void startMoveRight ( Mazub alien ) { } @ Override public void endMoveRight ( Mazub alien ) { } @ Override public void startDuck ( Mazub alien ) { } @ Override public void endDuck ( Mazub alien ) { } @ Override public void advanceTime ( Mazub alien , double dt ) { } @ Override public int getNbHitPoints ( Mazub alien ) { } @ Override public World createWorld ( int tileSize , int nbTilesX , int nbTilesY , int visibleWindowWidth , int visibleWindowHeight , int targetTileX , int targetTileY ) { } @ Override public int [ ] getWorldSizeInPixels ( World world ) { } @ Override public int getTileLength ( World world ) { } @ Override public void startGame ( World world ) { } @ Override public boolean isGameOver ( World world ) { } @ Override public boolean didPlayerWin ( World world ) { } @ Override public void advanceTime ( World world , double dt ) { } @ Override public int [ ] getVisibleWindow ( World world ) { <START_BUG> return Utilities . intVectorToArray ( world . getVisibleWindowSize ( ) ) ; <END_BUG> } @ Override public int [ ] getBottomLeftPixelOfTile ( World world , int tileX , int tileY ) { } @ Override public int [ ] [ ] getTilePositionsIn ( World world , int pixelLeft , int pixelBottom , int pixelRight , int pixelTop ) { } @ Override public int getGeologicalFeature ( World world , int pixelX , int pixelY ) throws ModelException { } @ Override public void setGeologicalFeature ( World world , int tileX , int tileY , int tileType ) { } @ Override public void setMazub ( World world , Mazub alien ) { } @ Override public boolean isImmune ( Mazub alien ) { } @ Override public Plant createPlant ( int x , int y , Sprite [ ] sprites ) { } @ Override public void addPlant ( World world , Plant plant ) { } @ Override public Collection < Plant > getPlants ( World world ) { } @ Override public int [ ] getLocation ( Plant plant ) { } @ Override public Sprite getCurrentSprite ( Plant plant ) { } @ Override public Shark createShark ( int x , int y , Sprite [ ] sprites ) { } @ Override public void addShark ( World world , Shark shark ) { } @ Override public Collection < Shark > getSharks ( World world ) { } @ Override public int [ ] getLocation ( Shark shark ) { } @ Override public Sprite getCurrentSprite ( Shark shark ) { } @ Override public School createSchool ( ) { } @ Override public Slime createSlime ( int x , int y , Sprite [ ] sprites , School school ) { } @ Override public void addSlime ( World world , Slime slime ) { } @ Override public Collection < Slime > getSlimes ( World world ) { } @ Override public int [ ] getLocation ( Slime slime ) { } @ Override public Sprite getCurrentSprite ( Slime slime ) { } @ Override public School getSchool ( Slime slime ) { } }

Fix:
return world . getVisibleWindow ( ) ;